Diagnostic Trouble Codes are often used by vehicle manufacturers to indicate an issue with components such as the engine of the vehicle. However, certain manufacturers such as Ford, set their parameters (minimum/maximum) for a misfire too wide of values so that a DTC for a potential or actual misfire is never set. Thus, causing difficulty to properly diagnosis a misfire is a cause of engine “sputter” or lack of power. Even when the “misfire” type data was available for Ford enhanced data using service 0x22 (request by common ID) in the pre-CAN years (i.e. FORD SCP engine systems), the “misfire data” would be hard to interpret as to which cylinder was misfiring. Starting with Ford CAN (Controller Area Network) engine systems, the “misfire” data was eliminated from the enhanced service using common ID's. Therefore, the “misfire” data was not available in CAN system type engine data streams for Ford in the Ford's enhanced data, which then frustrated the technicians.
Even when a technician can use a diagnostic tool to obtain “misfire” data of a cylinder, the “misfire” data if available is only a snapshot of cylinder firing data at that moment of time and thus, determining which cylinder or cylinders is misfiring is again difficult. For example, a misfire that occurs mainly between going from 2nd gear to 3rd gear of the transmission would be difficult to detect when only a one time “snapshot” of cylinders firing are shown to the technician. This is because the misfire is intermittent and thus the snapshot has to be at the right time.
In order to temper these frustrations, there is a need to be able to retrieve “misfire” data on enhanced CAN engine systems such as on a Ford and display it to the technician in order to properly diagnose the vehicle.